CZ20033010A3 - Modifier of emulsion explosive - Google Patents

Abstract

A modifier of brisance (i.e. shattering effect) for water-in-oil emulsion explosives, composed of a macromolecular component consisting of a prepolymer or polymer with the construction units-[CH2-C(X)=CH-CH2]-in its macromolecule where X is -H or -CH3, and which is terminated by hydroxi- or isocyanate groups or polyisobutylene groupings. Its use in an emulsion explosive reduces its brisance while preserving its working ability and raising the physical consistency of this explosive.

Description

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The water-in-oil emulsion explosive modifier consists of a macromolecular component consisting of a prepolymer or a polymer with building units [CH ₂ -C (X) = CH-CH ₂ ] - in its macromolecule, where X is -H or -CH ₃ as defined by hydroxyl or isocyanate groups or polyisobutylene moieties. Its application in an emulsion explosive reduces its brilliance to maintain working ability and increase the physical stability of the explosive.

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- 1 Emulsion explosive modifier

Technical field

The present invention relates to a water-in-oil emulsion explosive brizance modifier consisting of macromolecules. a component based on butadiene, liquid rubber, and / or isobutylene.

BACKGROUND OF THE INVENTION

When looking at water-in-oil emulsion explosives (code name W / O) as a mixture of chemical components, it is an oxidation-reduction system, as with most mixed explosives. The fuel-oxidant mixture is supplemented with a suitable non-explosive sensitizer that is able to participate by generating burning cores to initiate and develop a chemical reaction during detonation.

In most mixed explosives, the basic oxidant is ammonium nitrate, often in combination with other nitrates (eg sodium, potassium, calcium, lithium, etc.), or even perchlorates (sodium or ammonium). A wide, almost opaque palette of primarily carbonaceous compounds of mineral or synthetic origin is used as fuel (see, for example, W. Xuguang: Emulsion Explosives. Metallurgical Ind. Press, Beijing, 1994). The most commonly used fuels are paraffin oils and waxes, mineral, petroleum or vegetable oils, microcrystalline waxes and some petroleum fractions. The choice of a particular fuel or fuel mixture is determined by the requirements for the rheology of the resulting explosive and its physical and storage stability. The fuel phase may in some cases also comprise metal powders, in particular aluminum, and individually explosives such as demilitarized trinitrotoluene and / or hexogen and demilitarized propulsive explosives.

In conventional W / O emulsion explosives, the oxidation and fuel components are present in the liquid state: the discontinuous oxidant phase in the form of microspheres of a supersaturated oxidant solution and other water-soluble additives is dispersed in the continuous (oil) phase of the fuel microspheres (phase oxidants). The formation of a continuous and solid interface between the continuous and discontinuous phases is achieved by the addition of lipophilic-hydrophilic components to the oil phase, i.

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The emulsifiers most commonly used in technical practice are sorbitan monooleate and / or sesquioleate.

Strengthening of the continuous phase film and thereby increasing the physical stability of the resulting emulsion (emulsion matrix) can be achieved by adding some oligomers to the fuel phase, polymers and / or copolymers (see, eg, W. Xuguang: Emulsion Explosives. Metallurgical Ind. Press, Beijing, 1994) . In this context, the use of oligomers, polymers and resins based on isobutylene and butadiene is also described (see, for example, Canadian Patent Application No. CA 2,107,966 from 1994, or Japanese Kokai Tokkyo Koho JP 59,156,991 from 1984); liquid polybutadiene has a beneficial effect on enhancing emulsion stability. In the manufacture of these explosives, hydrophilic terminated polyisobutylenes sometimes appear as polymer emulsifiers, the use of which significantly increases the life of the final product.

The extremely large interfacial interface surfaces in the emulsion explosive matrix ensure perfect contact of both phases, which is the most perfect of all mixed industrial explosives. This fact corresponds to the short reaction zone in the detonation wave: with suitable sensitization and initiation, explosives of this type can be considered to be largely equivalent to dynamics due to the high reactivity of the system, the high utilizable energy yield and the resulting rock disintegration effect.

Compared to dynamites, i.e. explosives containing nitroesters, emulsion explosives have a number of significant advantages, such as insensitivity to mechanical stimuli, flames and sparks, high water resistance and minimal physiological activity not only of the emulsion composition itself, but also of explosion products. Emulsion explosives, however, can be phlegmatized, even quite numb, under the influence of dynamic shock, especially strong compression stress waves, induced by detonation of a near charge in the rock massif. Their further disadvantage is the fact that only Category I can be produced on the basis of emulsion explosives. Both of these disadvantages are related primarily to the relatively high brisance, i.e. the fragmentation effect, of the said type of explosives.

The most widespread principle of designing mining-safe explosives containing nitroesters is to incorporate a cooling additive, most often sodium chloride, or a cooling ion exchange system, such as a mixture of ammonium chloride and sodium nitrate, into the explosive mixture. This leads to a decrease in the working ability and brisance of the resulting explosive compared to nitroester explosives without coolants. However, as shown in the example section of this 4444 4444 4444 4444 4444 4444

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3 of the invention, analogous to the incorporation of sodium chloride in an amount of max. into the emulsion explosive mixture will decrease its working ability, but it will increase brisance. This can to some extent eliminate the cooling effect of said additive. The problem of emulsion explosives brisance is therefore a decisive factor in the construction of mine-safe explosives based on them. The data published so far show that the systematic study of the effect of the chemical nature of the components of the reduction-oxidation system of these explosives on their brisance has not yet been paid attention.

SUMMARY OF THE INVENTION

According to the process of the present invention, the water-in-oil emulsion explosive brisance is treated by adding to the oil phase a macromolecular component based on butadiene or isobutylene. The advantage of this procedure is that the relatively small addition of said macromolecular components (0.50 to 1.80% by weight based on the weight of the resulting explosive) significantly reduces brisance while maintaining the working ability of the emulsion explosive, while significantly increasing its stability and modifying the consistency of the resulting explosive. explosives, so that if the coolant is incorporated into its composition, it provides an explosive of category I mining safety. A further advantage of the process according to the invention is the availability of these macromolecular components which are manufactured industrially for the needs of the plastic or rubber industry, as well as for the production of special types of explosives.

The use of butadiene or isobutylene based macromolecular components within the meaning of the present invention has not been described in the literature so far and is documented by the following examples, which in no way exclude the possible variability of use patterns.

DETAILED DESCRIPTION OF THE INVENTION

Example 1

A solution of ammonium nitrate (AN) and optionally sodium nitrate (SN) and / or calcium nitrate (CN) and / or sodium perchlorate (SP) in water having a temperature of 85-100 ° C, optionally containing other water-soluble components such as is sodium chloride (SN),

-4-glycol and the like is impregnated into an emulsifier in which it is intensively mixed (with a stirrer at 1000 to 1500 rpm) an oil phase of 80-85 ° C warm, consisting of mineral oil (specific gravity 910 kg.m ^{- 3} , pour point max. -5 ° C and flash point min.66 ° C) and / or paraffin slack (pour point 39 ° C, flash point 220-260 ° C and oil content approx. 1.5% by weight) and sorbitan monooleate (M) and / or sorbitan sesquioleate (S), optionally also macromolecular components. After the inlet of the aqueous salt solution is complete, the mixture is stirred for a further 5 minutes. The emulsion matrix thus obtained is sensitized in a homogenizer by the addition of silicate microballoons (MB) with an average size of 70 µm, optionally also by the addition of solid sodium chloride (NaCl) with an average grain size of 80 µm. The resulting explosive mixtures are then loaded into plastic intestines prepared cartridges with a diameter of 32 mm and a weight of 400 g, which determine the specific charge weight (p), detonation velocity (D, initiation detonator No. 8) and relative working ability (RPS) . An overview of the composition of the individual mixtures prepared according to this procedure is given in the table, which also includes the respective p, D and RPS values.

The following are used as macromolecular components of the oil phase:

Liquid polybutadiene rubber (LBH) with terminal hydroxyl groups with an average molar mass of 2400-3100, a polydispersity index of approximately 1.1 and a hydroxyl content of approximately 0.7 mmol.g ^-1 , in which the number of structural units of its macromolecule - [CH ₂ - CH = CH-CH ₂ ] - is about 44 to 57.

liquid isocyanate prepolymer (LBD - terminated by isocyanatotolylene groupings) with a basic polybutadiene chain having an average molar mass of 3200-3800, a polydispersity index of about 1.3 and a functionality of about 2.2, in which the number of structural units of its macromolecule is - [Ct ^ -CH ^ CHCH ₂ ] - also about 44 to 57.

polyisobutadiene (PIB) solid copolymer with 2 mole%. isoprene with an average molecular weight of 200,000 of the general structural formula:

- [- (C (CH ₃ ) ₂ -CH ₂ -) _m - <- CH 2 -C (CH 3) = CH-CH 2 -) -] - wherein m »n.

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In some LBD emulsion mixtures, namely mixtures 1.1, 1.3 and 1.4 of the table, a crosslinking catalyst is used to obtain plastic, well-formable matrices capable of being filled with crystalline additives up to 50% by weight. without losing the consistency of the final mixture. Subject macromolecules! additives also increase the lifetime of emulsion explosives with their content (min. 6 months) compared to emulsion explosives without their content (lifetime 3 6 months).

Example 2

Proceed according to MS. No. 229,745 (1982): a solution of ammonium nitrate (AN) and sodium (SN) 80-90 ° C warm is introduced into an emulsifier, to which is added a solution of oleic acid in mineral oil and then an aqueous solution of sodium hydroxide. The mixture is stirred until an emulsion is formed which is sensitized in the homogenizer by adding expanded perlite. Thus, an emulsion explosive having a composition of 62.9 wt. AN, 13 wt. SN, 12 wt. % water, 2.5% sodium hydroxide, 2.8% wt. % oil, 2.8 wt. % oleic acid and 4 wt. of expanded perlite, which is declared as Emsit. Its specific charge weight is 1.06 g.cn &lt; -1 &gt;, the detonation velocity D = 4817 m.s &lt; -1 &gt; and the relative working capability RPS = 69.5%.

Example 3

The graphical dependence of the relative working ability (RPS) of the emulsion explosives of Example 1 and Example 2 on their brisance, represented by the product of the specific charge mass and the square of the detonation velocity, is constructed, ie p * D. This dependency implies that macromolecules! the components of the oil phase in Example 1 significantly reduce the brilliance of the respective emulsion explosives compared to explosives in which these components are not used (including Emsit of Example 2). This effect is significant in the production of mine-safe explosives. The graphical dependence also shows that for both groups of emulsion explosives the increasing content of solid particles with higher molar mass in detonation products corresponds to a decrease in RPS values and an increase in brizance, which also applies to the mineral sensitizer content.

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The composition of Example 1 in the form of a 32 mm diameter ladder mixture, when detonated at 1050 g, does not ignite a 9% by volume methane air mixture and at 1200 g a 300 g.m- ³ mixture of coal dust and air. of dust. The specified limit charge (32 mm diameter) of this explosive is 1241 ± 72 g. The gaseous products of its detonation do not contain nitrogen oxides.

Industrial applicability

Production of a water-in-oil emulsion matrix suitable for finalization into an emulsion explosive with suppressed shattering and retained sliding effect, eg on an explosive with increased mining safety.

Claims (2)

PATENT CLAIMS A water-in-oil emulsion explosive modifier comprising an intermittent phase of an aqueous solution of inorganic nitrates and / or perchlorates, optionally other components of inorganic and organic nature, optionally including a cooling component of the group of inorganic chlorides, characterized in that it consists of of a prepolymer or a polymer with building blocks - [CH 2 -C (X) = CH-CH 2] - in its macromolecule, where X is -H or -CH ₃ which is terminated by hydroxyl or isocyanate groups or polyisobutylene moieties. An emulsion explosive modifier according to claim 1, characterized in that it constitutes 0.5 to 1.8% by weight, preferably 0.6 to 1.57% by weight. explosives calculated on the weight of the final emulsion explosives.